黄沙河滨岸带沉积物营养盐的分布特征及释放规律

Distribution Characteristics and Release Regularities of Nutrients in Sediments in Huangshahe River Riparian Zone

为探讨黄沙河滨岸带沉积物中营养盐的释放规律,以3处不同营养盐水平的沉积物为研究对象,分析其表层沉积物（0~15 cm）的污染特征及空间分布规律,并采用原状泥柱对其营养盐的迁移方向及释放通量进行了研究。结果表明,沉积物中有机质和营养盐空间分布具有明显差异,各采样点总磷和有机质含量具有自底层向上不断递增的趋势,表层0~5 cm处沉积物中有机质和总氮在水平分布上自S1、S2、S3依次递减;水势决定沉积物中营养盐的迁移方向,不管是水势向上或向下,沉积物释放的营养盐均以溶解态为主,且增大水压会促进营养盐的释放;不仅沉积物的营养盐水平决定其营养盐的释放能力,沉积物的理化性质也是决定其营养物质释放通量的关键因素。

The pollution characteristics and spatial distribution regularities of nutrients in surface sediment columns（0～15 cm） at three sites located in Huangshahe river riparian zone were studied and the migration direction and emission flux of nutrients were also analyzed by using undisturbed soil columns to know the release regularity of nutrients in sediments in Huangshahe river riparian zone.The results showed that distribution of organic matters in sediments was significantly different with that of nutrients.The contents of total phosphorus and organic matters increased vertically from the bottom to surface of the sediment columns,and the contents of total nitrogen and organic matters decreased horizontally from S1 to S3;nutrients migration direction was decided by water potential,Nutrient released from sediments was mainly dissoluble nutrient no matter the water potential was upward or downward,and the nutrients release would increase with the increase of water pressure;The release capability of nutrients was not only determined by nutrient level of sediment,but also affected by physico-chemical property of sediments.